I hadn't worn a tie in years," says Trent Reznor, who rocked an elegant Prada tux when he accepted an Academy Award for Best Original Score. "It was fun to put the snarling-guy-sweating-on-a-mic on the shelf for a while." Reznor stunned Nine Inch Nails fans in 2009 by announcing an indefinite hiatus for the band. Since then, with pal Atticus Ross, Reznor has kicked off an intense collaboration with director David Fincher – including the Oscar – winning score for The Social Network and music for the upcoming adaptation of The Girl With the Dragon Tattoo. Last year, Reznor and Ross released an EP with their new band, How to Destroy Angels, which also includes Reznor's wife, Mariqueen Maandig. (The couple had their first child, a son, last fall.) "Being in a band with my wife, I'm very aware of the multitude of ways that can go wrong," says Reznor, 45, promising a new Angels LP this year. "We're best friends and are interested in the same things, so it's natural to make music together. Taking my personality out of the spotlight and working in a more supporting role is what's exciting to me now."

The main musical theme of Social Network is titled "Hand Covers Bruise." Why? I needed to come up with 18 names of songs in a day. I was faced with the task of "Let's not name it 'Mark Runs Across Campus'" [laughs]. When we were coming up with ideas of what the music would sound like, one of them happened to be called "Hand Covers Bruise," and it seemed to fit perfectly with that theme.

Did you expect to win? You think, "I'm probably not going to win, but if I do win, I'd better not sound like an idiot." The anxiety builds. Then you realize you haven't eaten in 12 hours. And the camera's on you, maybe, at all times. "I need to pick my nose, but I can't risk it." Then you hear your name in slow motion. "OK, hug my wife. Don't trip over the cord. Why am I taking steps two at a time? I'm going to slip, but I can't stop. Oh, my God, there's Nicole Kidman, she's nine feet tall. Is the mic on?" It's over in a millisecond, and you're backstage with an Oscar in your hand.

This word gets thrown around a lot at the Oscars, but who do you consider a genius? It's so obvious, but the Beatles. When I was growing up, the people who liked the Beatles, I didn't like, so I didn't pay attention to them. Around The Downward Spiral, I really started digging White Album-era Beatles, and it expanded outward from there. They were so far ahead of the game, it's just not fair. Also, Prince has been a huge influence, what he's able to do on his own. Exactly 20 years ago, you were preparing for the first Lollapalooza tour.

What are your most powerful memories from the summer of '91? We got a video on MTV, we heard our song on the radio, and then I got a call saying, "Jane's Addiction wants you to play this new festival." At our first show, in Arizona, our set lasted one and a half songs. I remember seeing Living Colour's pro road cases straight from Guitar Center and shiny spandex outfits, and I had a powder-blue cable that my dad gave me for Christmas when I was 15. It was 110 degrees in Arizona and a cable melted and our show was over. I just ran back to the bus. There were better shows after that.

What music do you play for your son? Mainly just piano: Bach, Beethoven and Mozart, a little Chopin. And recordings of womb sounds and clothes dryers to help him sleep. He will probably love David Lynch films. Right now the nursery sounds like Eraserhead [laughs].

You tweeted recently that you were watching old NIN footage, and it made you miss touring. When will NIN be back on the road? My reason for stopping touring with Nine Inch Nails is that I needed to force my own hand to make myself do something different. [NIN] is comfortable to me, familiar. I like those songs, I like singing those songs, I like the energy onstage, but it's not as relevant to me as it was when I was 25. And there's an unspoken pressure to keep touring – that's the only way to make a living – but I look at David Bowie's fearlessness in changing and reinventing himself. That takes courage. [The hiatus] won't be forever. The urge to tour again, in some capacity, will break through in the next few years.